It is known to use a flowing gas, such as air, as a power transmitting medium to a surface treating device. The device may be connected to the suction opening of a vacuum cleaner in order to produce a sufficient air flow to operate the surface treating device.
When air is used as a power transmitting medium, the device has a decided advantage over mechanical drive structures in its great flexibility. Moreover, the risk of the motor being damaged in the case of an overload is much smaller than in the case of a direct electric motor drive. Furthermore, it should be noted that a variety of tools can be selectively connected to the output shaft of the rotating fan unit, such as replaceable grinding, rubbing, brushing, scrubbing, or polishing tools. It will also become apparent that the same flowing air which operates the rotating fan unit can be used to carry away the particles of grinding dust materials.
A number of serious disadvantages have arisen in the use of air-operated grinding apparatus of the above-described type. One disadvantage is that the known grinding apparatus, after a short period of use, becomes clogged due to the accumulation of grinding particles in the air flow channels. This is especially true in the air paths to the rotating fan unit of the surface grinder. When the fan unit becomes clogged, a time consuming disassembly and cleaning operation becomes necessary. A further disadvantage of the known grinding apparatus construction is that the results of using a rotating grinding or polishing attachment are not satisfactory since very often circular marks are left on the work surface which cannot be eradicated.
It is an object of the present invention to overcome the aforesaid disadvantages by providing a surface treating attachment device in which the clogging of the rotating fan unit is effectively prevented, and at the same time, a much better surface treatment of the work area is achieved.
It is another object of the present invention to provide a means on the blades of a rotating fan unit for converting the rotating motion of this unit to an oscillating motion.
Another object of the present invention is to provide flow paths to the rotating fan unit of the proper dimensions in order to eliminate the possibility of the clogging of the fan unit assembly by dust particles generated by the grinding operation.
A further object of the present invention is to provide a unique handle construction in order to prevent or to substantially reduce or cushion the vibrations from being carried from the grinding mechanism to the handle.
An object of the present invention is to provide a quick connect and disconnect coupling for a vacuum cleaner hose which positively maintains the required vacuum in the device.
Another object of the present invention is to provide alternate embodiments of the present invention in which the surface treating device has a low overall structural height so that it can be easily operated under low furniture and the like.